Method of and apparatus for producing profile strips from sheet magnesium alloys



Sept. 15, 1931. E. DE RIDDER 1,823,439

' METHOD OF AND APPARATUS FOR PRODUCING PROFILE STRIPS FROM SHEETMAGNESIUM ALLOYS Filed Jan. 28. 1928 fnvenlor Frmf c Riiier PatentedSept. 15, 193 1 UNITE]? STATES, PATENT OFFICE ERNST. .DE BIDDER, OFIBITTERFELD, GERMANY, ASSIGNOR TO I. G. FARBEITINDUSTRIEAKTIENGESELLSCHAFT, OI FRANKFORT-ON-THE-MAIN, GERMANY, A CORPORATION OFGERMANY METHOD OF AND APPARATUS FOR PRODUCING PROFILE STRIPS FROM SHEETMAG- NESIUM ALLOYS Application filed January 28, 1 92 8, Serial No.250,314, and in Germany January 28, 1927.

' This invention relates to a method of producing profiled strips fromshaped sheets of magnesium alloys. Hitherto such strips were exclusivelyproduced by extruding in presses of known construction. However themanufacture of the required extruding dies for each single sort ofprofile is very expen- SIVQ.

I wish to point out, however, that my invention does not involve anymarked alteration of the thickness or to be shaped, but applies only tothe bending, or perhaps more pro erly expressed, folding of anoriginally recti inear cross section in a predetermined uniform manneralong the whole length of the strip. I

Now I have found that profiled strips up to a thickness of the materialof several millimetres may beproduced in afar simpler manner from rolledsheet metal strips or extruded strips by drawing, provided certainconditions are observed. 1

Of these conditions the first consists in maintaining a working temerature in the range of about 100 to 400 the temperature being raisedwith increasing thickness of the sheet and the stage of molding. Whenthe temperature of the metal is too low, it is not sufliciently ductile;at too high a temperature it is too soft, so that on drawing, the stripsare easily torn. The working temperature to be employed varies also tosome extent as is easily ascertained in each case according to thecomposition of the alloy under treatment and the efiect to be attained.A further condition which I found of special importance for treatingthese alloys is that the drawing should be effected through at least twodies. The dies are of different shape, the cut in the first die (thefore-die) I imparting only a preliminary shape to .the

sheet metal strip, in which the raw outlines of the profile areproduced, whereas the second die (the end-die) corresponds to the finalshape of the'profile in all its details.

These dies can be easily and cheaply manufactured as they may consistmerely of a plate of'moderately thi k sheet-steel or other hard metalinto which the profiles of the fore-die and the end-die are cut.

width of the strips When drawing a strip through dies of this characterin the obvious manner, i. e., by entering the strip in a verticaldirection to the plane of the dies, the planes of both dies eing in aparallel position, it is impossible to produce straight profiles, sincethe finished profiles have a tendency to curve longitudinally owing tothe stresses set up by the drawing process.

The principle underlying my invention now consists in counterbalancingthese stresses by preventing the rectilinear passage of the stripsthrough the dies, i. e., by passing the stripsthrough the dies at acertain angle of inclination to the direction of the drawing forces.

The angle of inclination necessary so as to exactly counterbalance thetendency of the strips to curve, i. e., to produce straight profiles,depends on the shape of the particular profile and-is easily ascertainedby experiment.

However, when in view of the further use of the finished profiles, it isdesired to obtain a definite curvature of the latter, this can likewisebe effected by fixing the angle of inclination of the strip so as todiffer from the angle of inclination as required for producing straightprofiles.

One method of earring out my drawing process consists in placing bothdies at a short distance, of say 5 to 20 centimetres, one after theother upon the drawing bench, in such a manner that the plane of thefore-die is not in parallel position to that of the end-die, but forms acertain angle of inclination therewith which angle may be finelyadjusted by suitable means. passing of the strips through both dies,parallel to the drawbench, is prevented.

In the annexed drawings, I have illustrated, by way of example, afore-die and an end-die and their mounting on a draw bench.

Fig. 1 is a vertical transverse section through the fore-die. Fig. 2 isa vertical transverse section through the end-die. Fig. 3 is a verticallongitudinal section of the apparatus consisting of a fore-die I,mounted by screws on a supporting ring 1', which is fixed on the drawbench d, and of an end- In this Way a rectilinear v I the strip betweenthe dies may also be effected die e, mounted correspondingly on 1' andd. If desired, as shown in Fig. 3, an intermediary member 2' may beemployed combining the rings 7' and 1', in a fixed distance one from theother, i being screwed on the draw bench. It should be mentioned,however, that in Fig. 3 the angle of inclination of the foredie has, forthe sake of clearness, been ex.- aggerated.

In certain cases the angle of inclination of by cutting the profile intothe fore-die not vertically but at a corresponding angle.

A further mode of arrangement for producing the straight profileconsists in rigidly connecting with each other the fore-die and.theend-die, both in parallel position, by an intermediate member andplacing the ensemble of dies at the required angle of inclination towardthe plane of the drawbench. Hereby it'is re \dered possible to providethe drawbench 1th an adjustable adapter suitable for any set of dies. Incase the shape of the desired profile requires an extremely large metals rips through the moulds begins and is continued, recourse being had,if desired, to the usual lubricants.

I claim 1. The method of producing profiled sections of uniformthickness from flat strips of magnesium alloys which comprises drawingsaid strips and subjecting continuously consecutive cross-sections ofsaid strips to at least two combinations of mechanical stressessimultaneously acting upon cross section's of the strips having adefinite longitudinal distance from each other and effecting a curvatureof the cross-section, the points of action of said combinations ofcurving stresses, with the exception of the ultimate one, being shiftedwith respect to the direction of drawing, thereby causing apredetermined deflection of the strips between the points of action oftwo consecutive combinations of stresses.

2. The'method of producing profiled sections of uniform thickness. fromflatstrips of magnesium alloys which comprises drawing said strips at atemperature between about 100 and 400 C. and subjecting continuouslyconsecutive cross-sections .of said strips to at least two combinationsof mechanical stresses simultaneously acting upon cross-sections of thestrips having a definite longitudinal disstance from each other andeffecting a curvature of the cross-section, the points of action of saidcombinations of curving stresses, with the exception of the ultimateone, being shifted with respect to the direction of drawing, therebycausing a predetermined deflection of the strips between the points ofaction of two consecutive combinations of stresses.

3. The method of producing profiled sections of uniform thickness fromflat strips of magnesium alloys which comprises drawing said strips andsubjecting continuously consecutive cross-sections of said strips to atleast two combinations of mechanical stresses simultaneously acting uponcross-sections of the strips having a definite longitudinal distancefrom each other, and effecting a curvature of the cross-section, thepoints of action of said combinations of curving stresses, with theexception of the ultimate one, being shifted with respect to thedirection of drawing,

thereby causing a predetermined deflection of the strips between thepoints of'action of two consecutive combinations of stresses, saiddeflection counterbalancing the curving effect of the stresses set up bythe drawing process in the finished profile.

4. A drawbench for drawing profiled sections of uniform thickness fromflat strips of magnesium alloys comprising, in operative combination, afore-die adapted to impart a preliminary curvature to the cross-sectionof said strips, and a final die placed at a definite distance from saidfore-die and adapted to impart the final shape to the 1 preliminarycurved cross-section of said strips, said dies being adapted to beinclined at a predetermined angle towards each other.

5. A drawbench for drawing profiled sections of uniform thickness fromflat strips of magnesium alloys comprising, in operative combination, aplurality of fore-dies adapted to impart successive curvatures to thecross-section of said strips correspondingto successiveintermediatestages of deformation of the cross-sections towards thepro-- file desired, and a final die adapted to impart the final shapetothe preliminarilycurved cross-section of said strips, said dlesbeingadapted to be inclined at a predetermined angle towards each other. 7

6. A drawbench for drawing profiled sec.- tions of uniform thicknessfrom flat strips of magnesium alloys comprising, in operativecombination, a support, means for adjusting said support at apredetermined angle to the drawbench plane, at least one fore-die andone final die placed at a definite distance from each other on saidsupport, and means for securing a predetermined 'angle of inclination ofsaid dies with respect to each other.

In testimony whereof I have hereunto set my hand.

I ERNST DE muons.

